The chronic administration of many chemical agents results in the appearance of malignant tumors in target tissues. These malignancies are characterized by alterations in control of cellular functions which suggest that mechanisms of genetic modulation have been altered. Recent evidence has accumulated which suggests that non-histone chromosomal proteins (NHCP) are involved in transcriptional control. The object of this proposal is to analyze these NHCP in normal liver, at well delineated stages of carcinogenic evolution and in the tumors which arise. We will use our previously described, intermittent dietary regimen of acetylaminofluorene (AAF) and examine liver exposed to subcarcinogenic doses, the premalignant nodules which arise with further exposure and subsequent malignant tumors. Additionally, the effects of a chronic regimen of diethylnitrosamine (DEN) will be evaluated. The effect of a single dose of DEN alone or in conjunction with partial hepatectomy and combination regimens consisting of short exposure to DEN or AAF followed by phenobarbital will be similarly studied. Cytosol, nuclei and chromatin will be isolated, purified and their proteins analyzed by isoelectric focussing followed by SDS-electrophoresis in the recently developed Iso-Dalt System. This system allows for the simultaneous resolution of 20 individual protein samples thereby eliminating electrophoretic variance due to casting gels individually, multiple buffer preparations and/or slight variance in power supply performance. The resulting electropherograms will be analyzed quantitatively and qualitatively to possibly detect proteins uniquely associated with the carcinogenic process.